Many objects include one or more refractive surfaces that refract light that is incident on the surface. For example, glass, water, a cornea part of an eye, as well as many other objects, include refractive surfaces. The refractive nature of the refractive surface causes the refractive surface, and any surface behind the refractive surface, to appear visually distorted.
One example of an object that includes a refractive surface includes an eye. Techniques for producing digital doubles in computer graphics tend to give little attention to details of a subject's eye. These techniques typically focus on reconstructing a skin surface of a subject and the appearance of the skin in increasing levels of detail. The visible portion of the eye is comprised of the white sclera, the transparent cornea, and the colored iris. Generic eye models used in computer graphics are insufficient for capturing the individual identity of a digital human. A manual process may be needed to create digital representations of eyes of characters, which requires a significant amount of effort.